Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
  • C07F7/02—Silicon compounds
  • C07F7/08—Compounds having one or more C—Si linkages
  • C07F7/10—Compounds having one or more C—Si linkages containing nitrogen having a Si-N linkage
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/16—Nitrogen-containing compounds
  • C08K5/20—Carboxylic acid amides
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
  • C08L83/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/14—Polysiloxanes containing silicon bound to oxygen-containing groups
  • C08G77/16—Polysiloxanes containing silicon bound to oxygen-containing groups to hydroxyl groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/20—Polysiloxanes containing silicon bound to unsaturated aliphatic groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/22—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen
  • C08G77/24—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen halogen-containing groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/22—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen
  • C08G77/26—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen nitrogen-containing groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/42—Block-or graft-polymers containing polysiloxane sequences
  • C08G77/44—Block-or graft-polymers containing polysiloxane sequences containing only polysiloxane sequences
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/70—Siloxanes defined by use of the MDTQ nomenclature
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31652—Of asbestos
  • Y10T428/31663—As siloxane, silicone or silane

Definitions

• the present invention relates to organopolysiloxane compositions containing polyacyloxysilanes and hardening very quickly with heat in the presence of an accelerator with a 2-carboxy-carboxamide group.
• the compositions of the invention are part of the family of self-accelerating curing silicone elastomeric compositions.
• compositions in contrast to the known single-component compositions hardening in the humidity of the air and also carrying acyloxy radicals linked to silicon atoms (described in particular in French patents 1,198,749, 1,220,348, 2,429,811 and European patent application EP-A-102 505 are not stable on storage but their crosslinking time is much shorter, for example of the order of a few minutes, up to 60 minutes. These known self-accelerated compositions must therefore be prepared immediately.
• compositions of the above type with rapid crosslinking duration are used in fields of application where this property is particularly advantageous such as for example the manufacture of seals " in situ "in the automotive industry.
• Compositions of the above type, bearing acyloxy radicals linked to silicon atoms, the crosslinking duration of which is independent of the humidity of the ambient air are known from French patent FR-A-1 193 721 where the accelerator is zinc oxide and by British patent GB-A-1 308 985, this patent describing a hardening process consisting in adding to the compositions 3 to 15% of a hardening accelerator constituted by a silico-aluminate before 5 to 10% by weight of water absorbed in order to manufacture molded parts in silicone elastomer by low pressure injection.
• compositions of this type are also described, but the hardening accelerator of which is chosen respectively from an alkali and alkaline earth hydroxide or else by a mixture consisting of water and a phosphate and / or an alkaline or alkaline earth polyphosphate.
• compositions described in these patents cannot be in a single package (monocomponent compositions) and must be conditioned in 2 components generally, on the one hand, the organopolysiloxane component and, on the other hand, the accelerator because the mixture of these two components must be done immediately before use, that is to say at the time of use.
• the object of the present invention is to provide an organopolysiloxane composition which can be monocomponent and which does not have the drawbacks mentioned above.
• the present invention also aims to provide a new hardening accelerator which, incorporated into organopolysiloxane compositions, does not cause the compositions to harden at room temperature in the absence of air humidity, but effectively accelerates the hardening of the compositions by energy supply in particular, by exposure to heat.
• an organopolysiloxane composition which can crosslink into an elastomer, characterized in that it comprises a polyhydroxylated polysiloxane A, a polyacyloxysilane B and an effective amount of a hardening accelerator C, chosen from at least one organic compound having at least one carboxy-2 carboxamide group optionally salified with a metal cation, preferably alkaline or alkaline-earth.
• the accelerator may preferably be a derivative of a phthalamic acid, a maleamic acid, or a succinamic acid or a polyhydrophthalic acid.
• these various accelerators can be mixed together and can also include any substituent having no adverse effect on the physicochemical properties of the cured elastomer. These various substituents may be carried by the groups (L) or (R).
• the accelerators according to the invention are preferably derivatives of phthalamic acids, or polyhydrophthalamic, succinamic or maleamic acids. These various compounds can also be represented by one of the following formulas, depending on the valence of R and the valence of the cation M,
• the accelerators which are particularly suitable are N, N 'ethylene bis maleamic acid and its calcium salt, N, N'-ethylene bis succinamic acid and its anhydrous or monohydrate calcium salt.
• the accelerators according to the invention can be formed from a mixture of compounds of the 2-carboxy-carboxamide type of formula 1, the carboxylic groups of which are free or salified. It is obvious that such mixtures can be obtained directly during the preparation of the accelerators according to the invention.
• ammonia butylamine, cyclohexylamine, hydrazine, aniline, chloroaniline, trifluoromethylaniline, toluidine, xylidine, 4,4-diamino diphenylmethane, diamino -4.4 'diphenyl ether, ethylene diamine, hexamethylene diamine, cyclohexylene diamine ...
• the various accelerators which can be used according to the invention the compounds of formula (I) in which the various symbols correspond exactly to the substituents carried by the acid anhydride (or the diacid or polyacid) and l amine (or diamine) used to prepare them and which have just been mentioned.
• the accelerator according to the invention in particular in its salified form may contain in its molecule, water of constitution in the form of a mono or polyhydrate salt. This water of constitution lowers the storage stability at room temperature of the single-component compositions generally within one month.
• the accelerator according to the invention in the case of a free acid generates water by intramolecular dehydration according to the reaction: and, in the case of a salt, generates the hydroxide of the corresponding metal cation M.
• This water and / or this hydroxide formed hydrolyzes the polyacyloxysilanes and therefore accelerates the crosslinking of the organopolysiloxane composition.
• this hydroxide neutralizes the acid originating from the hydrolysis of the polyacyloxysilane by generating water.
• composition according to the invention can also comprise from 1 to 150 parts of a mineral filler D per 100 parts of constituent A.
• Polymers A with a viscosity of 700 to 1,000,000 mPa.s at 25 ° C, preferably 1,000 to 700,000 mPa.s at 25 "C, are essentially linear polymers, consisting of diorganosiloxy units of the above-mentioned formula R 2 SiO, and blocked at each end of their chain by a hydroxyl group; however the presence of monoorganosiloxy units of formula RSiO 1.5 and / or siloxy units of formula Si0 2 , is not excluded in the proportion of at most 2% relative to the number of diorganosiloxy units.
• a-w-di (hydroxy) diorganopolysiloxane copolymers (A) are marketed; furthermore, they can be easily manufactured.
• One of the most common manufacturing techniques consists, in a first phase, in polymerizing diorganocyclopolysiloxanes using catalytic amounts of alkaline or acidic agents and then in treating the polymers with calculated amounts of water (French patents 1 134,005, 1,198,749, 1,226,745); this supply of water, which is all the higher as the polymers to be prepared have a lower viscosity, can be replaced in whole or in part by aw di (hydroxy) diorganopolysiloxane oils of low viscosity, for example ranging from 5 at 200 mPa.s at 25 ° C, having a high level of hydroxyl radicals, for example from 3 to 14%.
• the crosslinking agents (B) are used in an amount of 2 to 20 parts, preferably from 3 to 15 parts, per 100 parts of the polymers a-w di (hydroxy) diorganopolysiloxane (A).
• crosslinking agents (B) those corresponding to the following formulas can be cited:
• silanes of formulas there may be mentioned those of formulas below:
• the molar amount used of the silanes of formula: compared to that of the crosslinking silanes (B) of formula: is not narrowly defined, it is however necessary that it has an upper limit so that the mixture of the two types of silanes always contains on average at least 2.5 -OCOR 'groups for a silicon atom.
• the main role of the silanes of formula R " 2 Si (OCOR ') 2 is that of coupling the chains of the ⁇ - ⁇ di (hydroxy) diorganopolysiloxane polymers (A) which makes it possible to obtain elastomers having good physical characteristics when leaving of compositions containing polymers (A) whose viscosity is relatively low, for example ranging from 700 to 5000 mPa.s at 25 ° C.
• compositions according to the invention may also contain from 1 to 150 parts, preferably 5 to 120 parts, per 100 parts of the polymers a - ⁇ di (hydroxy) diorganopolysiloxane (A) of mineral fillers (D).
• mineral fillers D
• These fillers can be in the form of very finely divided products with an average particle diameter of less than 0.1 ⁇ m.
• these fillers (D) are combustion silicas and precipitation silicas; their specific surface is generally greater than 40 m 2 / g, and most often lies in the range 150 - 200 m 2 / g.
• curing catalysts are usually used in an amount of 0.0004 to 6 parts, preferably from 0.0005 to 5 parts per 100 parts of the polymers a - ⁇ di (hydroxy) diorganopolysiloxane (A).
• the organopolysiloxane compositions can also contain conventional adjuvants and additives, comprising in particular thermal stabilizers.
• thermal stabilizers comprising in particular thermal stabilizers.
• These latter products which, by their presence, improve the thermal resistance of silicone elastomers, can be chosen from salts, oxides and hydroxides of rare earths (and more especially from ceric oxides and hydroxides) or from oxides of titanium and iron obtained, preferably, by combustion.
• organopolysiloxane compounds can be introduced with the aim of acting on the physical characteristics of the compositions in accordance with the invention and / or on the mechanical properties of the elastomers derived hardening of these compositions.
• compositions are first of all prepared by mixing, protected from humidity, the constituents A, B, D and optionally the usual additives and adjuvants. They are stable in storage and harden only by exposure to humid air. It is obvious that such compositions could, if necessary, be used alone and their hardening or crosslinking, would then develop from the surfaces in contact with the ambient air and would continue gradually towards the interior of the mass. The duration of their complete hardening would be relatively slow and would depend mainly on the thickness of the layers deposited and on the hygrometric degree of the atmosphere surrounding the compositions. This would generally require a 24 hour period at room temperature, with a humidity of 60% to properly crosslink a layer 4 mm thick.
• compositions constitute the first component of a two-component composition in accordance with the invention, the second component being constituted by the accelerator C.
• the hardening accelerators C are added and homogenized to this first component, operating in the absence of air at room temperature.
• compositions are thus obtained, the stability of which at room temperature away from air humidity can range up to several months, or even more than a year, depending on the nature of the accelerator, the content of accelerator and storage temperature. Storage temperatures below 40 ° C, preferably below 25 ° C are preferred.
• compositions that cause or accelerate the hardening of these compositions, it is generally sufficient to subject them to a heat treatment at a temperature above 60 ° C., preferably between 80 and 250 ° C., more precisely still between 90 and 200 ° C.
• compositions thus accelerated, in accordance with the invention must then be used quickly since their hardening, in contrast to that of conventional single-component compositions, develops throughout the mass.
• the duration of their complete hardening is very variable since it depends on the nature and the quantities used of the accelerators C, on the temperature of the heat treatment and on the duration of the latter.
• the temperature is an important parameter; variations in the temperature have very clear repercussions on the curing speed. If the temperature increases (the variations are positive) the curing time is reduced; otherwise the duration is increased.
• the present invention also covers the two-component compositions where the accelerator C is stored apart from A, B, D and the usual additives or adjuvants. Such a presentation can be advantageous for applications where it is necessary to constantly adapt the accelerator content.
• Another object of the present invention is constituted by the use of fast-curing compositions for obtaining joints.
• compositions according to the invention can be used for multiple applications such as jointing in the building industry, assembly of the most diverse materials (metals, plastics, natural and synthetic rubbers, wood, cardboard, earthenware, brick, ceramic, glass, stone, concrete, masonry elements), insulation of electrical conductors, coating of electronic circuits, preparation of molds used for the manufacture of synthetic resin or foam objects.
• crushed joints are formed following the application of a bead of compositions with a bead on the contact zone between 2 metallic elements to be assembled.
• the beaded bead is first deposited on one of the elements then the other element is immediately applied to the first; this results in a crushing of the cord before it turns into an elastomer.
• This type of seal is intended for assemblies that should not be commonly dismantled (oil pan seals, timing case seals, etc.).
• the seal by its rubbery nature, follows all the irregularities of the surfaces to be jointed, therefore, it is unnecessary (1) to carefully machine the metal surfaces to be brought into contact with each other and (2) to tighten with force the assemblies obtained; these features allow to remove to some extent, fixing joints, spacers, ribs usually intended to stiffen and strengthen the elements of the assemblies.
• compositions in accordance with the invention can harden rapidly in the presence or absence of moisture, in a confined environment, or in ambient air, it follows that the joints "in shape" (and also the other joints " in situ ") resulting from the curing of these compositions can be manufactured under very restrictive conditions. They can, for example, be manufactured on the usual assembly lines of the automotive industry provided with an automatic device for depositing the compositions.
• This automatic device can have a mixing head for two-component compositions equipped with a depositing nozzle, which moves according to the profile of the joints to be manufactured.
• the mixing head can receive the polysiloxane composition comprising 1, accelerator, it can also have a third inlet allowing the introduction of a solvent used to rinse the installation after use (cyclohexane, etc.). Crosslinking can then be caused by appropriate heating of the bead or the deposited seal.
• compositions, manufactured and distributed by means of this device must have a well-adjusted hardening time, on the one hand to avoid solidification in the mixing head and on the other hand to obtain complete crosslinking after the end of the removal of the bead. peteux on the parts to be joined.
• this solidification can be avoided for single-component compositions in which the mixing head and the extrusion nozzle are maintained at ambient temperature.
• These "shaped" seals are more particularly suitable for seals of rocker covers, gearbox covers, distribution spacers and even oil sumps.
• compositions according to the invention are also suitable for the formation of fast-hardening joints in fields other than the automobile. They can therefore be used to glue and joint plastic electrical cabinets, to produce seals for vacuum cleaners and for steam irons.
• the elastomers resulting from the curing of the compositions in accordance with the invention have mechanical properties substantially similar to those of the elastomers derived from known single-component compositions therefore formed by simple mixing of the constituents A, B, D and optionally of usual additives without the introduction of the accelerators C.
• remanent compression strains can be relatively small, of the order of 8 to 35%, for example.
• the DRC test consists in heating for several hours (for example at 150 ° C.) an elastomer test piece maintained under compression reducing its height by 30% and in measuring the residual deformation by measuring in% the reduction in the test piece after the test.
• composition H 1 (thus obtained) comprising the accelerator, stored at room temperature (20 ° C) in closed tube, is stable at least 6 months as long as it is not in contact with the humidity of the air .
• test specimens are produced on polyethylene plates which are placed in an oven heated to 150 ° C. for 2 h.
• the test piece is completely crosslinked and has a maximum shore A hardness: 40.
• a DRC of 20% is measured on the test pieces by compression of 30% after 3 days at 150 ° C.
• the same accelerator is used as in Example 3 except that the calcium salt is dried under a vacuum of 1.5 mbar for 15 h at 60 - 65 ° C.
• the accelerator molecule contains practically no more water of constitution (residual water content of 1.4% by Karl Fisher assay).
• composition G 1 prepared in Example 1, 4.8 g of calcium salt under dry nitrogen are added and the composition H 4 thus obtained is placed in closed airtight tubes.
• composition F 5 is introduced under dry nitrogen into 100 g of composition G 1 prepared in Example 1 to obtain a composition H 5 .

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Silicon Polymers (AREA)
• Sealing Material Composition (AREA)
• Medicines Containing Material From Animals Or Micro-Organisms (AREA)
• Jellies, Jams, And Syrups (AREA)
• Medicines Containing Plant Substances (AREA)

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• 1985
  • 1985-05-03 FR FR8506735A patent/FR2581389B1/fr not_active Expired
• 1986
  • 1986-04-14 CA CA 506539 patent/CA1282530C/fr not_active Expired - Fee Related
  • 1986-04-29 BR BR8601909A patent/BR8601909A/pt unknown
  • 1986-04-30 EP EP19860420112 patent/EP0204641B1/fr not_active Expired
  • 1986-04-30 JP JP61098420A patent/JPS61254664A/ja active Granted
  • 1986-04-30 ES ES554539A patent/ES8704530A1/es not_active Expired
  • 1986-04-30 DE DE8686420112T patent/DE3663675D1/de not_active Expired
  • 1986-04-30 AT AT86420112T patent/ATE43620T1/de not_active IP Right Cessation
  • 1986-05-01 AU AU56900/86A patent/AU578149B2/en not_active Ceased
  • 1986-05-02 PT PT8250186A patent/PT82501B/pt not_active IP Right Cessation
  • 1986-05-03 KR KR1019860003490A patent/KR860009024A/ko not_active Ceased
• 1987
  • 1987-06-16 US US07/062,623 patent/US4755579A/en not_active Expired - Fee Related

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